docs: def getSignalLabels(self):
          """
          Returns all labels (name) ("FP1", "SaO2", etc.).
  
          Parameters
          ----------
          None
  
          Examples
          --------
          >>> import pyedflib
          >>> f = pyedflib.data.test_generator()
          >>> f.getSignalLabels()==['squarewave', 'ramp', 'pulse', 'noise', 'sine 1 Hz', 'sine 8 Hz', 'sine 8.1777 Hz', 'sine 8.5 Hz', 'sine 15 Hz', 'sine 17 Hz', 'sine 50 Hz']
          True
          >>> f._close()
          >>> del f
  
          """
          return [self._convert_string(self.signal_label(chn).strip())
                  for chn in np.arange(self.signals_in_file)]